1. Field of the Invention
This invention relates to a modular jack in which a modular plug is plugged.
2. Description of the Related Art
A modular jack is one of conventional connectors which are used in telephone equipment or local area network (LAN). The modular jack is usually mounted on a circuit board and the modular plug, which connects a plurality of core wires, such as cables, to each other, is plugged in the modular jack.
For example, as shown in FIGS. 13 to 16, Japanese Patent Application Kokai Number 2000-299164 discloses such a conventional modular jack. The modular jack comprises a housing body and eight terminals (the first to eighth terminals 3, 4, 5, 6, 7, 8, 9, and 10) provided in the housing body. The housing body is composed of an insert 11 and a modular jack assembly 12 for receiving the insert 11.
The insert 11 is composed of a rear wall 13 and a top wall 14 extending forwardly from the top of the rear wall 13. A predetermined number of upper grooves 15 are formed on the upper surfaces of the rear and top walls 13 and 14 and a predetermined number of rear grooves 16 are formed on the rear surface of the rear wall 13 such that the rear grooves 16 continues from the upper grooves 15 and extend in a vertical direction.
The respective terminals 3 to 10 are fixed to the rear wall 17 via an extended portion 17 and divided into two groups in accordance with the shapes thereof to reduce the electrical cross-talk. The first group consists of the first, third, fifth, and eighth terminals 3, 5, 7, and 10, and the second group consists of the second, fourth, sixth, and seventh terminals 4, 6, 8, and 9. As shown in FIG. 15(A), the respective terminals 3, 5, 7, and 10 of the first group have a fixed portion 18 fixed to a board 26, a vertical portion 19 extending vertically along the rear groove 16, a horizontal portion 20 extending horizontally along the upper groove 15, and a contact portion 21 folded back obliquely in a lower back direction at the end of the horizontal portion 20. The top of the contact portion 21 is a free end. As shown in FIG. 15(B), the respective terminals 4, 6, 8, and 9 of the second group have a fixed portion 22 fixed to a board 26, a vertical portion 23 extending vertically along the rear groove 16, a horizontal portion 24 extending horizontally along the upper surface of the rear wall 13, and a contact portion 25 curved downwardly from the end of the horizontal portion 24 and then extending obliquely in an upper forward direction. The top end of the contact portion 25 is supported by the front end of the top wall 14.
As shown in FIG. 16, the modular jack assembly 12 is mounted on the circuit board 26 and comprises sixteen receiving cavities 27 and 28 arranged in two-stage at the front side thereof. The insert 11 and the terminals 3 to 10 are arranged in the receiving cavity 28 of the lower stage and other insert and terminals (not shown) are arranged in the receiving cavity of the upper stage. Under this condition, the respective receiving cavities 27 and 28 are provided with plug-in cavities (not shown) in which the modular plugs are plugged.
When the modular plug is plugged in the modular jack, the contact portions 21 and 25 of the terminals 3 to 10 of the first and second groups are brought into contact with terminals (not shown) of the modular plug for electrical connection between the modular jack and plug.
In the conventional modular jack, however, it is required that the contact portions 21 of the terminals 3, 5, 7, and 10 of the first group are bent in the oblique lower back direction from the front end of the top wall 14 after the terminals are fixed to the insert 11. Accordingly, long-time assembly work and lengthy terminals are required, which makes it difficult to reduce the assembling and material costs. Also, a sufficient height of the housing body is necessary for bending the contact portions 21 in the oblique lower back direction, which makes it difficult to minimize the size of the housing body in the heightwise direction and the size of the modular jack.
In addition, since the housing body is composed of the insert 11 and modular jack assembly 12, which incorporate the respective terminals 3 to 10 into the housing body, it is difficult to reduce the number of parts and the manufacturing cost cannot be reduced.
Accordingly, it is an object of this invention to provide a modular jack, which makes it possible to reduce the assembling and material costs, minimize the size of the product, and reduce the number of used parts.
According to an aspect of the invention, a modular jack in which a modular plug is plugged, comprises a housing body including a cavity at a front side thereof in which the modular plug is plugged and a rear wall having openings and fixed portions, and a plurality of terminals fixed to the fixed portions and extend to the cavity in a form of cantilevered beams supported by the fixed portions, wherein the terminals are inserted into the openings to be fixed to the fixed portions.
It is preferable that the fixed portions include first and second fixed portions spaced from each other in a heightwise direction of the modular jack by a predetermined distance, wherein the first and second fixed portions are arranged alternately.
According to another aspect of the invention, the terminals include first terminals which are fixed to the first fixed portions and second terminals which are fixed to the second fixed portions, wherein the respective first terminals have first forwardly inclined contact portions and the second respective terminals have second forwardly inclined contact portions, wherein the first and second inclined contact portions have angles of inclinations which are different from each other.
It is preferable that the first and second inclined contact portions have first and second curved sections, respectively, at front ends thereof, wherein the first and second curved sections are disposed at different positions from each other in a back-and-forth direction.
Also, it is preferable that the housing has a plurality of control portions in a bottom wall thereof at positions corresponding to those of the terminals so that the terminals abut against the control portions to prevent excessive flexure of the terminals.
With the above-described structure, when the respective terminals are inserted into the openings in the rear wall of the housing body, they are firmly fixed to the housing body and extend to the plugging cavity in the form of cantilevered beams supported by the fixed portions.